CHANGELOG.md

@@ -22,9 +22,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
     * Configurable multithreading using `epoll`
 * Landerctl
     * `-c` flag to use custom config file (useful for testing)
-* LSM
-    * Binary tree iterators
-    * Trie iterators
 
 ## [0.2.0](https://git.rustybever.be/Chewing_Bever/lander/src/tag/0.2.0)
 

lsm/include/lsm.h

@@ -27,7 +27,6 @@ typedef enum lsm_error {
   lsm_error_null_value = 4,
   lsm_error_failed_io = 5,
   lsm_error_lock_busy = 6,
-  lsm_error_done = 7,
 } lsm_error;
 
 /*typedef struct lsm_string { */

lsm/include/lsm/bt.h

@@ -1,8 +1,6 @@
 #ifndef LSM_BT
 #define LSM_BT
 
-#include <stdbool.h>
-
 #include "lsm.h"
 
 /**
@@ -10,11 +8,6 @@
  */
 typedef struct lsm_bt lsm_bt;
 
-/**
- * A node inside an `lsm_bt` binary tree.
- */
-typedef struct lsm_bt_node lsm_bt_node;
-
 /**
  * Initialize a new binary tree
  *
@@ -75,33 +68,4 @@ lsm_error lsm_bt_remove(void **out, lsm_bt *bt, char key);
  */
 lsm_error lsm_bt_replace(void **out, lsm_bt *bt, char key, void *data);
 
-/**
- * Struct representing an in-flight iterator over the binary tree
- */
-typedef struct lsm_bt_iterator {
-  lsm_bt_node *next;
-} lsm_bt_iterator;
-
-/**
- * Initialize the given iterator for the binary tree.
- *
- * The iterator is explicitely allowed to be allocated by the user, as these are
- * commonly used inside functions where they can simply be stored on the stack.
- *
- * @param out iterator to initialize
- * @param bt binary tree to iterate
- */
-void lsm_bt_iter(lsm_bt_iterator *out, const lsm_bt *bt);
-
-/**
- * Advance the iterator to the next element.
- *
- * @param out where to store pointer to data; ignored if NULL
- * @param key_out where to store key; ignored if NULL
- * @param iter iterator to advance
- * @return true if a new entry was returned, false if the iterator has no more
- * entries to return
- */
-bool lsm_bt_iter_next(void **out, char *key_out, lsm_bt_iterator *iter);
-
 #endif

lsm/include/lsm/trie.h

@@ -1,10 +1,7 @@
 #ifndef LSM_TRIE
 #define LSM_TRIE
 
-#include <stdlib.h>
-
 #include "lsm.h"
-#include "lsm/bt.h"
 #include "lsm/str.h"
 
 /**
@@ -12,11 +9,6 @@
  */
 typedef struct lsm_trie lsm_trie;
 
-/**
- * A node inside an `lsm_trie` trie
- */
-typedef struct lsm_trie_node lsm_trie_node;
-
 /**
  * Initialize a new trie.
  *
@@ -65,36 +57,4 @@ lsm_error lsm_trie_remove(void **out, lsm_trie *trie, const lsm_str *key);
  */
 uint64_t lsm_trie_size(const lsm_trie *trie);
 
-/**
- * Represents an in-flight iterator over a trie
- */
-typedef struct lsm_trie_iterator lsm_trie_iterator;
-
-/**
- * Initialize an iterator to iterate over all entries with keys starting
- * with the given prefix.
- *
- * @param out pointer to store iterator pointer in
- * @param trie trie to iterate
- * @param prefix prefix of the keys; a zero-length string means iterating over
- *  the entire trie; NULL is interpreted as a zero-length string
- */
-lsm_error lsm_trie_iter(lsm_trie_iterator **out, const lsm_trie *trie,
-                        const lsm_str *prefix);
-
-/**
- * Advance the given iterator.
- *
- * @param out pointer to store next data pointer in
- * @param iter iterator to advance
- * @return `lsm_error_ok` if next element has been returned, `lsm_error_done` if
- *  no more elements are present, or some other error code
- */
-lsm_error lsm_trie_iter_next(void **out, lsm_trie_iterator *iter);
-
-/**
- * Free the given iterator.
- */
-void lsm_trie_iter_free(lsm_trie_iterator *iter);
-
 #endif

lsm/src/_include/lsm/bt_internal.h

@@ -9,13 +9,12 @@
 /**
  * Node inside a binary tree
  */
-struct lsm_bt_node {
+typedef struct lsm_bt_node {
   struct lsm_bt_node *left;
   struct lsm_bt_node *right;
-  struct lsm_bt_node *parent;
   void *data;
   char key;
-};
+} lsm_bt_node;
 
 /**
  * Initialize a new binary tree node

lsm/src/_include/lsm/trie_internal.h

@@ -5,11 +5,14 @@
 #include "lsm/str_internal.h"
 #include "lsm/trie.h"
 
-struct lsm_trie_node {
+/**
+ * A node inside a trie structure
+ */
+typedef struct lsm_trie_node {
   lsm_bt bt;
   lsm_str skip;
   void *data;
-};
+} lsm_trie_node;
 
 /**
  * Allocate and initialize a new trie node
@@ -30,13 +33,4 @@ struct lsm_trie {
   uint64_t size;
 };
 
-struct lsm_trie_iterator {
-  lsm_trie_node *next;
-  struct {
-    lsm_bt_iterator *arr;
-    size_t len;
-    size_t cap;
-  } stack;
-};
-
 #endif

lsm/src/bt/lsm_bt.c

@@ -1,6 +1,5 @@
 #include <stdlib.h>
 
-#include "lsm/bt.h"
 #include "lsm/bt_internal.h"
 
 lsm_error lsm_bt_node_init(lsm_bt_node **ptr, const char key, void *data) {
@@ -61,12 +60,10 @@ void lsm_bt_free(lsm_bt *bt) {
 uint64_t lsm_bt_size(const lsm_bt *bt) { return bt->size; }
 
 lsm_error lsm_bt_insert(lsm_bt *bt, char key, void *data) {
-  lsm_bt_node *parent = NULL;
   lsm_bt_node **dest = &bt->root;
 
   // Traverse down the tree until we reach the new point to insert our node
   while ((*dest != NULL) && ((*dest)->key != key)) {
-    parent = *dest;
     dest = key < (*dest)->key ? &(*dest)->left : &(*dest)->right;
   }
 
@@ -74,8 +71,9 @@ lsm_error lsm_bt_insert(lsm_bt *bt, char key, void *data) {
     return lsm_error_already_present;
   }
 
-  LSM_RES(lsm_bt_node_init(dest, key, data));
-  (*dest)->parent = parent;
+  if (lsm_bt_node_init(dest, key, data) != lsm_error_ok) {
+    return lsm_error_failed_alloc;
+  }
 
   bt->size++;
 
@@ -127,27 +125,13 @@ lsm_error lsm_bt_remove(void **out, lsm_bt *bt, char key) {
     (*dest)->data = (*succ)->data;
 
     lsm_bt_node *succ_replacement = (*succ)->right;
-    lsm_bt_node *parent = (*succ)->parent;
-
     lsm_bt_node_free(*succ);
-
     *succ = succ_replacement;
-
-    if (*succ != NULL) {
-      (*succ)->parent = parent;
-    }
   } else {
     lsm_bt_node *replacement =
         (*dest)->left != NULL ? (*dest)->left : (*dest)->right;
-    lsm_bt_node *parent = (*dest)->parent;
-
     lsm_bt_node_free(*dest);
-
     *dest = replacement;
-
-    if (*dest != NULL) {
-      (*dest)->parent = parent;
-    }
   }
 
   return lsm_error_ok;
@@ -172,45 +156,3 @@ lsm_error lsm_bt_replace(void **out, lsm_bt *bt, char key, void *data) {
 
   return lsm_error_ok;
 }
-
-void lsm_bt_iter(lsm_bt_iterator *out, const lsm_bt *bt) {
-  out->next = bt->root;
-
-  if (bt->root != NULL) {
-    // Initialize the iterator to the smallest element in the tree
-    while (out->next->left != NULL) {
-      out->next = out->next->left;
-    }
-  }
-}
-
-bool lsm_bt_iter_next(void **out, char *key_out, lsm_bt_iterator *iter) {
-  if (iter->next == NULL) {
-    return false;
-  }
-
-  if (out != NULL) {
-    *out = iter->next->data;
-  }
-
-  if (key_out != NULL) {
-    *key_out = iter->next->key;
-  }
-
-  if (iter->next->right != NULL) {
-    iter->next = iter->next->right;
-
-    while (iter->next->left != NULL) {
-      iter->next = iter->next->left;
-    }
-  } else {
-    while ((iter->next->parent != NULL) &&
-           (iter->next->parent->right == iter->next)) {
-      iter->next = iter->next->parent;
-    }
-
-    iter->next = iter->next->parent;
-  }
-
-  return true;
-}

lsm/src/trie/lsm_trie_iter.c

@@ -1,117 +0,0 @@
-#include "lsm.h"
-#include "lsm/trie_internal.h"
-
-/**
- * Advance the iterator so that `next` now points to a node containing data. If
- * no more data nodes are found, `next` is set to NULL. The initial value of
- * `next` is ignored.
- */
-lsm_error lsm_trie_iter_next_data_node(lsm_trie_iterator *iter) {
-  do {
-    // Traverse back up the stack until we reach either the end of the subtree,
-    // or an iterator that hasn't been exhausted yet
-    while ((iter->stack.len > 0) &&
-           !lsm_bt_iter_next((void **)&iter->next, NULL,
-                             &iter->stack.arr[iter->stack.len - 1])) {
-      iter->stack.len--;
-    }
-
-    if (iter->stack.len == 0) {
-      iter->next = NULL;
-
-      return lsm_error_ok;
-    }
-
-    // Add node's subtree to the stack
-    if (iter->stack.len == iter->stack.cap) {
-      lsm_bt_iterator *arr = realloc(
-          iter->stack.arr, iter->stack.cap * 2 * sizeof(lsm_bt_iterator));
-
-      if (arr == NULL) {
-        return lsm_error_failed_alloc;
-      }
-
-      iter->stack.arr = arr;
-      iter->stack.cap *= 2;
-    }
-
-    lsm_bt_iter(&iter->stack.arr[iter->stack.len], &iter->next->bt);
-    iter->stack.len++;
-
-  } while (iter->next->data == NULL);
-
-  return lsm_error_ok;
-}
-
-lsm_error lsm_trie_iter(lsm_trie_iterator **out, const lsm_trie *trie,
-                        const lsm_str *prefix) {
-  uint64_t prefix_len = prefix == NULL ? 0 : lsm_str_len(prefix);
-
-  uint64_t index = 0;
-  lsm_trie_node *node = trie->root;
-
-  // Simplified traversal down the trie to find the root of the subtree
-  // contaiing all nodes with the given prefix
-  while ((index < prefix_len) && (node != NULL)) {
-    char c = lsm_str_char(prefix, index);
-    lsm_error res = lsm_bt_search((void **)&node, &node->bt, c);
-
-    switch (res) {
-    case lsm_error_ok:
-      index += 1 + lsm_str_len(&node->skip);
-      break;
-    case lsm_error_not_found:
-      node = NULL;
-      break;
-    default:
-      return res;
-    };
-  }
-
-  lsm_trie_iterator *iter = calloc(1, sizeof(lsm_trie_iterator));
-
-  if (iter == NULL) {
-    return lsm_error_failed_alloc;
-  }
-
-  iter->next = node;
-
-  if (node != NULL) {
-    lsm_bt_iterator *arr = malloc(sizeof(lsm_bt_iterator));
-
-    if (arr == NULL) {
-      free(iter);
-
-      return lsm_error_failed_alloc;
-    }
-
-    iter->stack.arr = arr;
-    iter->stack.cap = 1;
-    iter->stack.len = 1;
-
-    lsm_bt_iter(&iter->stack.arr[0], &node->bt);
-
-    if (node->data == NULL) {
-      LSM_RES(lsm_trie_iter_next_data_node(iter));
-    }
-  }
-
-  *out = iter;
-
-  return lsm_error_ok;
-}
-
-lsm_error lsm_trie_iter_next(void **out, lsm_trie_iterator *iter) {
-  if (iter->next == NULL) {
-    return lsm_error_done;
-  }
-
-  *out = iter->next->data;
-
-  return lsm_trie_iter_next_data_node(iter);
-}
-
-void lsm_trie_iter_free(lsm_trie_iterator *iter) {
-  free(iter->stack.arr);
-  free(iter);
-}

lsm/test/bt/bt.c

@@ -104,33 +104,6 @@ void test_remove_multiple() {
   lsm_bt_free(bt);
 }
 
-void test_iter() {
-  char chars[] = "falcoep";
-  size_t char_count = sizeof(chars) / sizeof(char) - 1;
-
-  char sorted_chars[] = "aceflop";
-
-  BT_INIT();
-
-  for (size_t i = 0; i < char_count; i++) {
-    TEST_CHECK(lsm_bt_insert(bt, chars[i], (void *)(i + 1)) == lsm_error_ok);
-  }
-
-  lsm_bt_iterator iter;
-  lsm_bt_iter(&iter, bt);
-
-  char key;
-  void *data;
-  size_t i = 0;
-
-  while (lsm_bt_iter_next(&data, &key, &iter)) {
-    TEST_CHECK_(key == sorted_chars[i], "%c == %c", key, sorted_chars[i]);
-    i++;
-  }
-
-  TEST_CHECK(i == char_count);
-}
-
 TEST_LIST = {
   { "bt init", test_init },
   { "bt insert first", test_insert_first },
@@ -138,6 +111,5 @@ TEST_LIST = {
   { "bt insert multiple", test_insert_multiple },
   { "bt remove root", test_remove_root },
   { "bt remove multiple", test_remove_multiple },
-  { "bt iter", test_iter },
   { NULL, NULL }
 };

lsm/test/trie/trie.c

@@ -25,64 +25,8 @@ void test_insert_one() {
   TEST_CHECK(data == (void *)1);
 }
 
-void test_iter() {
-  TRIE_INIT();
-
-  lsm_str *s;
-
-  lsm_str_init_copy(&s, "hello");
-  TEST_CHECK(lsm_trie_insert(trie, s, (void *)1) == lsm_error_ok);
-
-  lsm_str_init_copy(&s, "hella");
-  TEST_CHECK(lsm_trie_insert(trie, s, (void *)2) == lsm_error_ok);
-
-  lsm_str_init_copy(&s, "hel");
-  TEST_CHECK(lsm_trie_insert(trie, s, (void *)3) == lsm_error_ok);
-
-  lsm_str_init_copy(&s, "wow");
-  TEST_CHECK(lsm_trie_insert(trie, s, (void *)4) == lsm_error_ok);
-
-  lsm_str_init_copy(&s, "hel");
-
-  lsm_trie_iterator *iter;
-  TEST_CHECK(lsm_trie_iter(&iter, trie, s) == lsm_error_ok);
-
-  void *data;
-
-  TEST_CHECK(lsm_trie_iter_next(&data, iter) == lsm_error_ok);
-  TEST_CHECK_(data == (void *)3, "%p == %p", data, (void *)3);
-
-  TEST_CHECK(lsm_trie_iter_next(&data, iter) == lsm_error_ok);
-  TEST_CHECK_(data == (void *)2, "%p == %p", data, (void *)2);
-
-  TEST_CHECK(lsm_trie_iter_next(&data, iter) == lsm_error_ok);
-  TEST_CHECK_(data == (void *)1, "%p == %p", data, (void *)1);
-
-  TEST_CHECK(lsm_trie_iter_next(&data, iter) == lsm_error_done);
-  lsm_trie_iter_free(iter);
-
-  // Test full trie iterator
-  TEST_CHECK(lsm_trie_iter(&iter, trie, NULL) == lsm_error_ok);
-
-  TEST_CHECK(lsm_trie_iter_next(&data, iter) == lsm_error_ok);
-  TEST_CHECK_(data == (void *)3, "%p == %p", data, (void *)3);
-
-  TEST_CHECK(lsm_trie_iter_next(&data, iter) == lsm_error_ok);
-  TEST_CHECK_(data == (void *)2, "%p == %p", data, (void *)2);
-
-  TEST_CHECK(lsm_trie_iter_next(&data, iter) == lsm_error_ok);
-  TEST_CHECK_(data == (void *)1, "%p == %p", data, (void *)1);
-
-  TEST_CHECK(lsm_trie_iter_next(&data, iter) == lsm_error_ok);
-  TEST_CHECK_(data == (void *)4, "%p == %p", data, (void *)4);
-
-  TEST_CHECK(lsm_trie_iter_next(&data, iter) == lsm_error_done);
-  lsm_trie_iter_free(iter);
-}
-
 TEST_LIST = {
   { "trie init", test_init },
   { "trie insert one", test_insert_one },
-  { "trie iter", test_iter },
   { NULL, NULL }
 };